CVE-2023-3640

HIGHNVD 7.87.0▼
EchelonGraph scoreMEDIUM confidence

Score 7.0 from GitHub Security Advisory (severity: HIGH) published 2023-07-24. NVD baseline CVSS 7.0; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Elevated
7.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 7.8Exploit: NoneExposed: 0

A fix is available — apply it.

A possible unauthorized memory access flaw was found in the Linux kernel's cpu_entry_area mapping of X86 CPU data to memory, where a user may guess the location of exception stacks or other important data. Based on the previous CVE-2023-0597, the 'Randomize per-cpu entry area' feature was implemented in /arch/x86/mm/cpu_entry_area.c, which works through the init_cea_offsets() function when KASLR is enabled. However, despite this feature, there is still a risk of per-cpu entry area leaks. This issue could allow a local user to gain access to some important data with memory in an expected location and potentially escalate their privileges on the system.

CVSS v3
7.8
EG Score
7.0(medium)
EPSS
51.5%
KEV
Not listed

Published

July 24, 2023

Last Modified

July 21, 2026

Advisory Details (3)

Auto-updated Jun 26, 2026
Patch available. Sources: redhat.
redhat Patch Available

2217523 – (CVE-2023-3640) CVE-2023-3640 Kernel: x86/mm: a per-cpu entry area leak was identified through the init_cea_offsets function when prefetchnta and prefetcht2 instructions being used for the per-cpu entry area mapping to the user space

https://bugzilla.redhat.com/show_bug.cgi?id=2217523
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2023-3640
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.

https://access.redhat.com/errata/RHSA-2023:6583

Vendor Advisories for CVE-2023-3640(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatkernel-0:5.14.0-362.8.1.el9_32023-11-07redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 10× in last 7d / 47× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 108 total refreshes for this CVE.

  1. 2026-07-22 14:06 UTCEPSS rescore
  2. 2026-07-21 15:23 UTCEPSS rescore
  3. 2026-07-21 15:23 UTCEPSS rescore
  4. 2026-07-20 17:06 UTCEPSS rescore
  5. 2026-07-19 14:29 UTCEPSS rescore
  6. 2026-07-19 02:27 UTCEPSS rescore
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  9. 2026-07-16 17:01 UTCEPSS rescore
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  11. 2026-07-15 16:56 UTCEPSS rescore
  12. 2026-07-15 16:56 UTCEPSS rescore
  13. 2026-07-15 14:19 UTCOSV refresh
  14. 2026-07-15 01:58 UTCEPSS rescore
  15. 2026-07-13 22:28 UTCEPSS rescore
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  17. 2026-07-13 06:11 UTCEPSS rescore
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  23. 2026-07-09 19:08 UTCEPSS rescore
  24. 2026-07-08 15:13 UTCEPSS rescore
  25. 2026-07-07 13:44 UTCEPSS rescore
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  1. 2026-07-06 16:26 UTCEPSS rescore
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  3. 2026-07-06 02:22 UTCEPSS rescore
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  5. 2026-07-04 06:29 UTCEPSS rescore
  6. 2026-07-01 15:05 UTCEPSS rescore
  7. 2026-06-30 23:21 UTCEPSS rescore
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  9. 2026-06-28 14:06 UTCEPSS rescore
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  11. 2026-06-28 04:55 UTCEPSS rescore
  12. 2026-06-28 04:55 UTCEPSS rescore
  13. 2026-06-27 14:34 UTCOSV refresh
  14. 2026-06-27 03:07 UTCEPSS rescore
  15. 2026-06-27 03:07 UTCEPSS rescore
  16. 2026-06-26 11:39 UTCNVD updateCVSS v3 → 7.8
  17. 2026-06-25 13:48 UTCEPSS rescore
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  19. 2026-06-24 14:04 UTCEPSS rescore
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  21. 2026-06-23 21:31 UTCEPSS rescore
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  23. 2026-06-22 14:24 UTCEPSS rescore
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  25. 2026-06-21 14:55 UTCEPSS rescore
  26. 2026-06-21 14:55 UTCEPSS rescore
  27. 2026-06-21 01:58 UTCEPSS rescore
  28. 2026-06-21 01:58 UTCEPSS rescore
  29. 2026-06-19 19:24 UTCEPSS rescore
  30. 2026-06-19 19:24 UTCEPSS rescore
  31. 2026-06-18 17:51 UTCEPSS rescore
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  36. 2026-06-15 17:47 UTCEPSS rescore
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  38. 2026-06-14 23:16 UTCEPSS rescore
  39. 2026-06-13 22:59 UTCEPSS rescore
  40. 2026-06-13 22:59 UTCEPSS rescore
  41. 2026-06-12 23:10 UTCEPSS rescore
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  43. 2026-06-11 13:59 UTCEPSS rescore
  44. 2026-06-11 13:59 UTCEPSS rescore
  45. 2026-06-10 22:17 UTCEPSS rescore
  46. 2026-06-10 13:21 UTCEPSS rescore
  47. 2026-06-10 13:21 UTCEPSS rescore
  48. 2026-06-10 01:17 UTCOSV refresh
  49. 2026-06-08 14:16 UTCEPSS rescore
  50. 2026-06-08 14:16 UTCEPSS rescore
  51. 2026-06-07 15:23 UTCEPSS rescore
  52. 2026-06-07 15:23 UTCEPSS rescore
  53. 2026-06-06 13:46 UTCEPSS rescore
  54. 2026-06-06 13:46 UTCEPSS rescore
  55. 2026-06-05 22:46 UTCEPSS rescore
  56. 2026-06-05 22:46 UTCEPSS rescore
  57. 2026-06-05 06:09 UTCEPSS rescore
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  59. 2026-06-05 06:09 UTCEPSS rescore
  60. 2026-06-04 13:11 UTCEPSS rescore
  61. 2026-06-04 13:11 UTCEPSS rescore
  62. 2026-06-02 20:12 UTCEPSS rescore
  63. 2026-06-02 20:12 UTCEPSS rescore
  64. 2026-06-01 13:51 UTCEPSS rescore
  65. 2026-06-01 13:51 UTCEPSS rescore
  66. 2026-05-31 22:30 UTCEPSS rescore
  67. 2026-05-31 22:29 UTCEPSS rescore
  68. 2026-05-31 00:15 UTCEPSS rescore
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  70. 2026-05-29 13:43 UTCEPSS rescore
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  72. 2026-05-28 13:44 UTCEPSS rescore
  73. 2026-05-28 13:43 UTCEPSS rescore
  74. 2026-05-27 13:39 UTCEPSS rescore
  75. 2026-05-27 13:39 UTCEPSS rescore

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCpray77/CVE-2023-3640
    First seen Jun 20, 2023

    SCTF 2023 kernel pwn && CVE-2023-3640

    Open source ↗

Frequently asked(5)

What is CVE-2023-3640?
CVE-2023-3640 is a high vulnerability published on July 24, 2023. A possible unauthorized memory access flaw was found in the Linux kernel's cpuentryarea mapping of X86 CPU data to memory, where a user may guess the location of exception stacks or other important data. Based on the previous CVE-2023-0597, the 'Randomize per-cpu entry area' feature was implemented…
When was CVE-2023-3640 disclosed?
CVE-2023-3640 was first published in the National Vulnerability Database on July 24, 2023, with the most recent update on July 21, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2023-3640 actively exploited?
CVE-2023-3640 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 51.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2023-3640?
CVE-2023-3640 has a CVSS v3 base score of 7.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 7.0.
How do I remediate CVE-2023-3640?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2023-3640, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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